Today I experienced a firewire drive failure on my mini. To determine which drive was bad was a bit difficult since the apple profiler does not show serial number information about the drives and the firewire id can change depending on which drive was ready first, etc. After the experience I now have the following steps to take to make this easier in the future. The follow was done after I replaced the bad drive — There also appears to be a Disk Utility issue with disk replacements do I went the terminal window instead.